SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c693fb102bded0f4a633d440c02d42d0e462a1dd875a38bcf4fdb59f4c5ce60' 
  AND token = '1keQpt8rjF9riARNOeH259nR7bZQVImRXZ03mkXE6LI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}