SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85e60656e8d69e50f06fd42061043941682240d797193a2428d0b3e2338ae217' 
  AND token = 'n/v4j3IFmoJCRNkD9+iySQukBD2fqk4r3rDSf28Ch6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00078

JSON explain

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