SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c19adfc1463f44852b2e8e53e580afa48b1bc5978d21ee8c6b835c7b2368be' 
  AND token = 'ZvOJDoFjChmZ1Bw70VEuybGDGPNzHLOomif6tJ+rjng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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