SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8747606ca78a6c96711087dd0b5b3520db9071a66e1ba9bb88c70ad92557159' 
  AND token = 'TA3jLfZVvJBexWiNkzfhyYfeyh42V0CQR8pqkmV/ICs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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