SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1d48d04efc344799bb7abaf4527bffea1c7fa2ea57330f608c4856eb94e3eb9' 
  AND token = '+RA6RpCZR6BfreHtG8Z1sVM8CPAyHoLYGhxRxu3hPdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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