SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '233b5258009db75e327edc6577c9189da41bb79987629214edbfb109ff7b4c5b' 
  AND token = 'ONxLTE/xDPgRN5qPAlDkSflOuCsRqIo9XATG4Iu5kQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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