SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'abfcf1763f216f946e453b7c90c11818936a88db8c6fbfdf379ea3d308518774' 
  AND token = 'jF0roXS2x7bHYMmE3zCeS+K9nQduIppHBbSeRtRF+fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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