SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a736376a3bbf481dc731083e34c2c27e1b6ba8f91aee1971a8040de649668e15' 
  AND token = 'Xy3EUOWB8LhM5l3Rn7lrnzNQ2vnIfDCBSduIRSnogk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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