SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fea05d217c73768bdc72183c20cce052b88bd2dec1bb02556b16108068d399e' 
  AND token = 'BzybxxxXVvQA8w9atmL+VVpgolcq4iM2osJJ7HJ70B0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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