SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c7c663a61c04653e69bdab9be0e35cfc7064152456403b5cc28820eb3c04a77' 
  AND token = 'cexn5SAaJV3EJ6IeBwfUnjVM1z97xrAGqhoTSUNt2b0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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