SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f75357d8725f194216e6f6260a108024d6f806421147b23fadf6c97e1e124cf3' 
  AND token = 'oru7SOTEQQ5mvvUPrbDORYYbWDxmCqhWpFzTuzt7kAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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