SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a36530b3fe5c80aaf4290f9a6a7cb27f36ab657f061a108cec4eee586be3fa5' 
  AND token = 'ZSVxyVFJWnEJA8tAcbB44Ox9bw6JApEihhLK+8pfafg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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