SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926262453e16dbeb637be3a7347b436fc7a1bb20ea19a7c0748f43174af9d790' 
  AND token = '01SLGRKh9j+omJu8j4BiDlsQxumpwXJ1oeo4jHiLYiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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