SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2816da2aaefca9fb630c0d2fd4968cab3a017b254b42ed14a5687da51b08cec4' 
  AND token = 'EGpwl9Vvj0DIfnEwEWNPtiQUU7IH+Bi13JwL1Z36x1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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