SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '872eeaa0810bc265ab563996cc20e86a4fb47d04f484f83fd2e2a99e25865891' 
  AND token = 'ZiGCrvi7miAYCdSK5ckbVjNdVTF4kEzUEhan/nBIav4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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