SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ac1f1f8e8c40aad676506dd1305b0f8364ed576ce93429903ad387900fe6a79' 
  AND token = 'pxAXnqM/UHZ1huZ5xHV+R+txYHPFK4d4XbBX4AW2ljw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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