SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d4fac05d1f6192628e01409ec097650dd1b368661301d442a524a64deeaf7b1' 
  AND token = 'pKaM8HRnGuIsFXqSS65DaCYA1FMBqdovG8UKaJO5qFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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