SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc0babeb2cfb658fa76ab11799b240cd38a189687e29af2537b2ba3134da45fc' 
  AND token = '2oiU+YtkTuDNSVGZJoXjIZsg1BYB89vCTyTzOL2Zonc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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