SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7d2f63827f0c09922964c48f98cde9c3d5990d308068a345a2daf0f3e1ddbbc' 
  AND token = 'PEascsq4Cdrfxjiu2fAvkcI3z8UqDVlYewugNVxWzco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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