SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eff0ea9d8e2936c36b7a4227c10b32013b8bfa2346f3aa577315d03dcaad8cb1' 
  AND token = 'QlQMU7eIPZwahGKKZ2I+1EVHba5lH+0/pbN+2B4pPrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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