SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70ffd8143de04bec04c5b642c7ac17231fa1b9eaa9d479747523c7b4f3e91a9d' 
  AND token = 'aRaPoMlH3DL+SFDXgn3oWDGlnDj+gQzaSqj3vLPfRiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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