SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f1f1226dcaf924efc1be62da196c787550fb0b9b46c3888f05e2de74a6c1371' 
  AND token = 'HdIqSiqQYTdZhD3+XSl78Rv9FaPAzdamszcApxp8yBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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