SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3322092f81739423216b727728d41c9e5c13e33b46e74b8a8d36b8eb57a2da9' 
  AND token = '/ugyu1ry+tdwKjZPA9PiJTSpDYLhr32974Bh5NxZmc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}