SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c2d5101e679f06f067a2d286e7228072b3a64e54a2a000c289df30cdf4b53be' 
  AND token = 'qcB2Rkh/mjQMWLOmPzbPMCSXB7Ae7tkn0pKlijXgfik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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