SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea17a54fad8b0190bd9cda833d7be2748acb51a28b0c12763a479c12961fff87' 
  AND token = 'b2i3AUctcxLC9DhhSb82Hx5snxRfp0limc4NgcJUoeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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