SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0acbea2513ee0903684061ea4572a402025bd495e6f19c81d184f1cdfe07abb8' 
  AND token = 'UASZPSvLPFn3zeyCID+sthUBNWqfglJYqtruwlLlrwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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