SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fc4c10c9b3f7bc1ca83a9f4dc2c529668871c54e2a9820cef829ab209f3f70ba' 
  AND token = '+9MUfFHSNvP2/5d4Wzmu3WW8KKYZfjHBA4pXYWKmHZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}