SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25055289c118ae35263b3dc6f0423820eada904be4846138e481597fcc3d34e9' 
  AND token = 'ML1MvHgtIyKSpNF06vLDOKCT1PJgchce6k+9S3rvJEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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