SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1cf72ff4a79364fd9d3b97bf80da08c68677646040bde0b49c2eca869cc21fec' 
  AND token = 'iwoH+0v3Kfa8GmiRZfqPdb26wo2vJ5klZrfiZD/93GY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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