SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be51304260b1d43b74fef8186589229e4d1c931f16c39dc7e9dd7724961833e4' 
  AND token = 'aaEf+t5j+8LAIaO6/SZyjIQ2Pmc5dNZwEnOXAGO7Bwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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