SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1df3aaae86eeb15682aa3087310e0e445171011fc8f6c4df50e50aad741cfd1' 
  AND token = 'bIDCq13JiyoCMRFHtgHwuiHPv5fBwW9xKZqqVAZ/Hx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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