SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c552e6f76561e6ccc0be80ab30a58a3ad6f0222442b54617b92603207f131ee6' 
  AND token = '3vrNCI/i9KrE3tNCm0cBcookrG0zBLfJ/qhrTP6rhPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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