SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5ccf21ab61c08e01188b3cbf7175996322babd5f57d606b816de37c1cb1e163' 
  AND token = 'RPobb/c2utMOOSY/8LW8VYhpRvvaNMRXv3on5BI41uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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