SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91ea651b0ac131747215cd0ed126c90bc2023b958428e4964298092580377bf8' 
  AND token = 'ftBCa0oZPTS4XuHFbNxOoCC5ecX54Jk82GKtp4tXjJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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