SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cab26358d8259fccb2b354dec876ca5daaffed5ee4c07783920bc79204d85df8' 
  AND token = 'kvWqdl+OnbqjKLUSVQPcCVCDOdh7lsKjwljps9HLAGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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