SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c0f1198c7b15f26af46e61df53dd2a2e6c831341aba2bab92c485ecf386e625' 
  AND token = 'dZAWGml5ZBSMhsHsCDegHwP027+yFONOk2kEPNEdUAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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