SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e18ffee722e85a2b2244bef1feb8309ca142692fc6ef03d39098ab881c895d00' 
  AND token = 'FV34nKJ+aWkqktx5K2Rr2rxnRCrQpJTbUtu5XTR9Nsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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