SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcc247e88013e6ad6c4621295d8af9442aa188995c28140ce600caea0434196d' 
  AND token = 'Gt/hYM73zszZCPmXPMdo1x6luMqSmxuv4i059HPSPJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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