SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43d3c50841c4d6e769a181ac37d03dbd0ddcac530671e98084c0137e159dc579' 
  AND token = 'YaV8H7vREzDWNbiLdnuX2Ds8YGQbM7cbhN4u6pUPrzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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