SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ea4a2d64683787901acd8f761118afac50bab57c326dbbf42439c4db25364685' 
  AND token = 'iFfgJRLyNsfZgKiSebVIEyd1kJBFStad9qgzY+wiETs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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