SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b2174324ca9b94395402ccaba337b02aebee7e3f2e8fa0e4d58de4cea5d42e6' 
  AND token = 'REbXvqHLxf0Qu/G9zssWVyo4r370qvyeBN1vPDIveCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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