SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8bd38c5c60e5eccfe9887f6c7bde90c87ff57576eb6856f39889ac6ee805ebf' 
  AND token = 'viC6PiQqExO/MKlFLZYokJ87d8urmlCH81MKYuvkqoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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