SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b43667086860e9be772786946dd95ac4afc3263103283b65800ad4e654dffdfc' 
  AND token = '+Af3scFiwLWozSTFCJAVZ5aHRevm5J9aj8vVEbG87cs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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