SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b2066a9bd13a5af8fc0dc5885b62117b64b448a421af7a4c6241469377e1051' 
  AND token = 'uFxl3Dt+RuN3EXhLsKR2TsbMUnZvCMWRZ0eRSDWthLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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