SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c64ebe948ef3eb3a2aaec291a20ded975a772e5bb2ac8b97e18265130906a3a' 
  AND token = 'XoOBXvCNVeDbexzcL+7E6e8p9niESK9ZG40Gz9XIkoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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