SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaf8f885b4f74b822539fcc8d393707a61dca53d716532dd15bc5539e049d7bb' 
  AND token = 'L1qmFwxOeacU56w8z7yUKAqQIRXzsSltdakwmG2NNWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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