SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dd0e104e889b99dce00b60c68936b1b7ce22aad2d97e41960474b3092c68f98' 
  AND token = '3pfYnJQUeJz44ATrQVOXksETKqCHcmxgY8NlHeKYRFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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