SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ed357b1bdcb745c656bcfdac34d148b6d11843bde207341640886307c29d726' 
  AND token = 'sKTgehyKm7HdhPn0ublotuo7cE8phkVBnVI52GA9B60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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