SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7844f9ae73f3cb3597ff5272f374d29b0192db305f70aec0b17510971e677d5' 
  AND token = 'Qbvw8LajuXwGOq8PFt8D1hyQK+Nd7V/yRBplMlj5rGQ=' 
  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"
    }
  }
}