SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc47114123cffda02ac1e61c62b4701b8363acafc0811c995e0f43d781642fb8' 
  AND token = '81GRSCYa/Irj3WfFjSEw6M8YI3yfow5HQkjq1vCRnXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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