SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1282e20c74b2e54fdf35d60c18f3e4643197f3eb8a1c6c2639acb69dc767f9' 
  AND token = 'LaKNsaHUxDG5BwFBwjukRIcFtwxJh+c2DSnqPig3m5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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