SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a797a50455a51fafbe7416766c2c6b0c7aa6a49142a7f2e77c1773480bbab1d6' 
  AND token = 'E5D0xB//iiQJYealHCSWWhDuXlCoGeNAsd4qbl91U00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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