SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeb00131fe37c13ef461e3ed22c6da95f2c6c75b8892926c86b3ec9ce5f2b199' 
  AND token = 'Bm8DB5hiH00HwamP0lYXZX4aM1x07Bf21ulkFO0Ygds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}