SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b80cc5b61f47bccded794dfd77f633385269a0194d82061ecd354ef495ff693' 
  AND token = 'hakhILAwF6ISvHIZp2cfb0fcOWFybiGqgZwkoj+A0sc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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