SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71974cc9b6761ee8a6a7fb51bc9456561701d32fc93ef90237921bfa0fad9d8c' 
  AND token = 'v5VVJJumlAViX6qqomcXUzUjzAzQYNe2BEOuZi7dZ2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00074

JSON explain

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